Virtual reality in vestibular diagnosis and rehabilitation

While vestibulo-oculomotor and vestibulo-spinal functions are usually investigated by means of electronystagmography and stabilometry, environmental exploration and navigation cannot be easily studied in the laboratory. We propose that virtual reality (VR) can provide a solution, especially for those interested in the assessment of vestibular influence over spatial cognitive activities. Subjects exposed to immersive VR show rotatory behaviors during exploration that are the result of both a lateralized vestibular dominance and of the interplay with ongoing cognitive activity. The effect of vestibular dominance over exploratory behavior disappears in nonimmersive VR conditions, but certain patterns of exploratory movements still seem to be associated to cognitive performance. On these grounds, we propose the use of VR to improve current techniques of vestibular rehabilitation based on visual feedback. We describe a new equipment that combines the functions of a digital stepping analyzer with those of a PC VR workstation. The patient controls the navigation of virtual environments by means of appropriate displacements of the center of gravity. The combination of a closed-loop feedback to control displacements of the center of gravity and active exploration of the environments makes an otherwise static exercise contingent on a viridical representation of spatial navigation.